Uhh, it varies, really. There's music that's simple because the musicians don't know how to be make interesting music, and then there's music that's simple beca

Uhh, it varies, really. There's music that's simple because the musicians don't know how to be make interesting music, and then there's music that's simple because that's the musically correct thing to do and the musicians have the confidence to be like "no, we're not playing all the notes and doing all the things right now". There's layers of sophistication. Sometimes becoming a better musician means learning to put more into a song, and sometimes it means less. A good example of this: Ahmad Jamal, Surrey With The Fringe On Top, particularly the section 50 seconds in - https://www.youtube.com/watch?v=tM7PDwzY9LA https://www.youtube.com/watch?v=tM7PDwzY9LA More mainstream is the drumming in "Seven Nation Army" by the White Stripes.